Well, the heat wave is not a bright mark for France, but it remains unclear at this point what could have been done to avoid it, beyond having AC in every single house, which is maybe not the cheapest way to save lives...

the heat wave really was unusual, in that not only daytime temperatures were extremely high, but so were night time temperatures. It was the fact that the bodies never had a moment of respite from the heat for several days and nights running that killed the weaker ones. That was extremely unusual. As critics of France don't usually believe in globa lwarming, there is no sense in planning for such a freak event to happen again, right?

post hoc studies have shwon that the vast majority of deaths happened to people that were well taken care of, either with their families or in rest homes with enough staff. The fact that the media coverage focused on the few that were isolated or on the difficulties that ER rooms (real enough, these) does not invalidate that general fact;

mortality in 2004 was extraordinarily low, thus suggesting that the 2003 heatwave "anticipated" some deaths. (And don't call me callous, I am just talking statistics. As a matter of fact, a colleague's mother dies during the heat wave, something pretty much unexpected as she was in good health).

So the real lessons of that catastrohpe were as follows:

the government found to its detriment that it could not close down completely in August, and that it needed to be able to react to real needs when they arose (they did not in 2003, which created confusion, lack of coordination and poor inforation all around, and that's also why it became a big story). This year, like last, the government is visible during August...

ER services need to be reinforced. Like in the US, they have become the first port of call for a number of people that do not have full coverage and cannot go to a doctor - or whose doctor is on holiday that month. They were overwhelmed that month and need more support. A plan was prepared, although I cannot really tell you that the situation has been solved yet.

practical stuff that can be done in a heatwave had now been publicised more widely (take baths, drink a lot of water and the like), and public buildings are encouraged to have at least one "fresh" room.